Into.the.Void.

It’s been a while since ivman stopped working on my Gentoo box but I never had the time nor the willingness to take a look into it. It appears that ivman is incompatible with some newer versions of hal and dbus. The good thing is that there’s an alternative, it’s called halevt and as far as I’ve taken a look into it the configuration options look quite straightforward.
For Gentoo, there are ebuilds for halevt on Gentoo bugzilla, which install just fine.

In my point of view there’s an issue here for Gentoo. Latest ivman (sys-apps/ivman-0.6.14) compiles just fine against all of its dependencies, but then it does nothing at all when a deviced is plugged in. If the devices are present when ivman starts then it can detect and mount them, if you plug the devices after ivman is started, then ivman does nothing at all. I think ivman is broken since hal 0.5.9.X versions. Gentoo developers stll keep ivman in the stable tree though. I find no real logic to this decision. Ivman is buggy with current stable hal and dbus. I would prefer a de-stabilization of ivman or even a package mask for it. What’s the point in keeping a package (ivman) in the stable tree since it requires not the latest stable but an older version of another package (hal) ? IMHO, since they correctly decided to stabilize hal 0.5.11-r8, which subsequently rendered ivman useless, ivman should be wiped from the stable tree.
Some bugs on ivman reported on Gentoo Bugzilla: http://bugs.gentoo.org/buglist.cgi?quicksearch=ivman

I once used ivman with a couple of custom scripts to create/remove icons of automounted devices on my ROX desktop. I think I can make these scripts work again with halevt…I am in the process of rewriting them. More on that in the following days…

Filed by kargig at 01:06 under Gentoo,Linux
Tags: automount, bug, bugzilla, Gentoo, hal, halevt, ivman, Linux, rox
7 Comments | 11,327 views

If you have an IMAP server based on Courier-IMAP and you get complains from people using the default Mail.app on Mac OS X about getting many warning messages and not being able to connect, the remedy is to increase the maximum allowed concurrent sessions per IP. They possibly have multiple accounts on the server and Mail.app is not able to handle each connection properly.
The cure is to open up /etc/courier-imap/imapd-ssl and /etc/courier-imap/imapd, find the MAXPERIP setting and change it to something like:
MAXPERIP=10

Don’t forget to restart your courier-imap server for changes to take effect.

By default the MAXPERIP setting is set to 4. On the imapd-ssl file it’s not even included in the config file (but still set to 4) so you need to add it yourself.

Filed by kargig at 12:20 under Linux,MacOSX
Tags: configs, courier, imap, Linux, MacOSX, mail, maxperip, ssl
No Comments | 9,378 views

comzeradd send me an e-mail about a mysql service not starting in a server we administer. I started taking a look around…nothing seemed suspicious.
I tried uninstalling and re-installing mysql-server-5.0 a few times and I always got this kind of output from apt-get:

Stopping MySQL database server: mysqld.
Starting MySQL database server: mysqld . . . . . . . . . . . . . . failed!
invoke-rc.d: initscript mysql, action “start” failed.
dpkg: error processing mysql-server-5.0 (–configure):
subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
mysql-server-5.0
Reading package lists… Done
Building dependency tree
Reading state information… Done
Reading extended state information
Initializing package states… Done
Reading task descriptions… Done

(more…)

Filed by kargig at 19:35 under Linux
Tags: bind-address, debian, init, Linux, loopback, mysql
2 Comments | 4,938 views

Μετά από ένα τρομερό Σαββατοκύριακο στη Λάρισα γυρίσα πάλι πίσω στη Θεσσαλονίκη. Το Fosscomm 2009 ήταν πάρα πολύ καλά οργανωμένο και τα παιδιά του Linux Team ΤΕΙ Λάρισας αξίζουν πολλά συγχαρητήρια για την προσπάθειά τους.

Τα παιδιά μας είχαν κλείσει ξενοδοχείο και ήταν πάρα πολύ ωραίο να μένουν 60+ άτομα που όλοι κουτσά στραβά γνωρίζονται στο ίδιο ξενοδοχείο. Θυμίζε πενταήμερη! Επίσης είχαν τυπώσει μπλουζάκια (πρόλαβα και πηρα ένα), κονκάρδες και διάφορα άλλα. Μιας και η συμμετοχή στο συνέδριο ήταν μεγάλη, θεωρώ πως μόνο το Σάββατο πρέπει να ήταν πάνω από 200 άτομα, θα είχε μεγάλο ενδιαφέρον να δούμε τις απαντήσεις στο ερωτηματολόγιο αξιολόγησης της εκδήλωσης που είχαν στο stand τους και όποιος ήθελε συμπλήρωνε.

Έξω από το επαρκέστατα εξοπλισμένο αμφιθέατρο, υπήρχαν stand με έντυπο υλικό καθώς και CD/DVD από διάφορες κοινότητες. Εκεί ήταν το Foss.Ntua, η ΕΕΛΛΑΚ, ο HELLUG, η ελληνική κοινότητα Fedora και η ελληνική κοινότητα Freebsd. Φυσικά παρόν ήταν και η ομάδα του Linux Team ΤΕΙ Λάρισας με το δικό της stand. Το κλίμα ήταν γενικώς πάρα πολύ καλό και συνάντησα πολλούς φίλους και γνωστούς που είχα μήνες να τους δω.

Θεωρώ πως οι παρουσιάσεις ήταν γενικά καλές, θα τολμήσω να πω πως ήταν ανώτερες από το επίπεδο του περσυνού Fosscomm που είχε γίνει στο Μετσόβειο, αλλά κυριώς ευχαριστήθηκα τα workshops που πέρυσι έλειπαν εντελώς. Συγχαρητήρια σε όσους κόπιασαν για να τα διοργανώσουν γιατί ένα καλό workshop είναι πολύ πιο δύσκολο από μια απλή παρουσίαση…Δυστυχώς και φέτος υπήρξαν κάποιες ακυρώσεις ομιλιών, ελπίζω του χρόνου τα πράγματα να κυλήσουν πιο ομαλά 🙂

Αν και δεν είδα όλες τις παρουσιάσεις γιατί προτίμησα να περάσω κάποιο παραπάνω χρόνο με φίλους και γνωστούς στους διαδρόμους, από όσα είδα έμεινα εντυπωσιασμένος από την δουλειά που έχει γίνει στη Σχολή Ικάρων από τον κύριο Αντώνιο Ανδρεάτο. Είμαι σίγουρος πως πολλοί καθηγητές των δικών μας πανεπιστημίων, ακόμα και από σχολές πληροφορικής, θα ντρεπόταν αν έβλεπαν τα βήματα προόδου σχετικά με τη χρήση και διάδωση ελεύθερου λογισμικού που έχουν κάνει στην Σχολή Ικάρων. Επίσης ευχαριστήθηκα πάρα πολύ την παρουσίαση του Android που έκανε ο Κώστας Πολυχρόνης. Με έψησε ακόμα περισσότερο να αποκτήσω το HTC Magic…με τσουρούφλησε θα έλεγα. Δεν θα μπορούσα να παραλείψω φυσικά το workshop και την παρουσίαση του Gentoo, που είναι και το αγαπημένο μου distribution, και έγινε από φίλους. Επίσης το Xen workshop, από την κοινότητα ανοιχτού λογισμικού του Πανεπιστημίου Πειραιά, με έβαλε και πάλι σε σκέψεις για να αρχίζω να πειραματίζομαι ξανά με το xen. Η κοινότητα αυτή μας είχε κανει πέρυσι (2007-2008) την τιμή να ανοίξουμε (εγώ και ο Fuzz) μια σειρά από εκδηλώσεις/παρουσιάσεις που ακολούθησαν και μάλιστα βράβευσαν το iloog ως το καλύτερο ελληνικό open source project για το 2008 στην περσινή DTE!

Είμαι επίσης πολύ χαρούμενος που αρκετός κόσμος με ρωτούσε τι γίνεται με το iloog και αν θα βγει ξανά καινούργια έκδοση. Μου έδωσαν ώθηση να συνεχίσω να ασχολούμαι μαζί του και υπόσχομαι να βγάλω μια έκδοση μέσα στους επόμενους μήνες. Ελπίζω φυσικά σε αυτό να βοηθήσουν και κάποιοι άλλοι …αν έχουν ακόμα όρεξη (στραβοκοιτάζω προς τον Fuzz και τον comzeradd αν δεν το έχουν ήδη καταλάβει)….

Το highlight του σαββατοκύριακου όμως ήταν η έξοδος μας το σάββατο το βράδυ. Τα παιδιά του ΤΕΙ Λάρισας ήρθαν και μας πήραν από το ξενοδοχείο και ένα τεράστιο τσούρμο 50+ ανθρώπων περπατούσαμε μέσα στην Λάρισα για να φτάσουμε τελικά σε ένα τσιπουράδικο. Εκεί οι φωτογραφίες, που θα αρχίσουν φαντάζομαι να δημοσιεύονται σε λίγες μέρες, θα μαρτυρύσουν το τι έγινε 😀

Τι μου άρεσε:
α) Η οργάνωση
β) Κάποιες παρουσιάσεις και κυρίως τα workshops
γ) Που είδα φίλους και γνωστούς

Τι δεν μου άρεσε:
α) Που φέτος ήρθαν λιγότεροι Αθηναίοι…
β) Που κάποιες παρουσιάσεις ακυρώθηκαν για λόγους που δεν ανακοινώθηκαν (δεν αναφέρομαι προφανώς σε εκείνους που τους έτυχε κάτι έκτακτο…)

Τι θα ήθελα για του χρόνου:
α) Αντί για 10 παρουσιάσεις κοινοτήτων θα προτιμούσα ένα session με εκπροσώπους από όλες τις κοινότητες σε ένα panel, όπου για 1h να μας παρουσιάσουν τα των μελών τους. Δεν χρειάζεται η κάθε κοινότητα να μας λέει πόσα μέλη έχει στο forum/mailing lists/etc σε ξεχωριστή παρουσίαση. Αυτό μπορεί να γίνει από όλους μαζί…
β) Περισσότερα projects από τις κοινότητες. Προσωπικά με ενδιαφέρει περισσότερο να δω ότι ένα άτομο από την τάδε κοινότητα ξεκίνησε κάτι και τον βοήθησαν οι υπόλοιποι παρά να βλέπω ότι 1500 καινούρια μέλη γράφτηκαν στο forum τους.
γ) Καλύτερη παρουσίαση όχι τόσο των events της κάθε κοινότητας αλλά περισσότερο του τρόπου με τον οποίο τα οργάνωσαν. Αυτό λείπει κυρίως, έλλειψη οργάνωσης και εκεί θέλουν βοήθεια οι περισσότερες κοινότητες (αλλά και οι σύλλογοι).
δ) Ακόμα περισσότερα workshops.

Το Linux Team ΤΕΙ Λάρισας ανέβασε πολύ ψηλά τον πήχη αλλά ελπίζω το επόμενο Fosscomm, το Fosscomm 2010, όπου και να γίνει, να είναι ακόμα καλύτερο!

Συγχαρητήρια και πάλι 🙂

Filed by kargig at 13:16 under Gentoo,Greek,Linux
Tags: Android, fosscomm, fosscomm 2009, Gentoo, Linux
4 Comments | 5,980 views

I was given root today in a gentoo box that nobody had upgraded since 2007. As expected the “emerge –sync; emerge -uDavt world” showed a lot of blockages.

I tried to solve each one but I got stuck while trying to upgrade portage 2.1.3.9 to 2.1.6.11. In order to upgrade portage I had to upgrade sandbox, but sandbox couldn’t be ugraded correctly due to portage 2.1.3.9 being unable to handle .tar.lzma files.
The box had sandbox-1.2 installed and it was unable to upgrade to sandbox-1.6. The error was:

unpack sandbox-1.6.tar.lzma: file format not recognized. Ignoring.

Upgrading lzma-utils, tar and a few other packages did not work. In the end I edited the sandbox-1.6-r2.ebuild and changed the src_unpack function from:
src_unpack() {
unpack ${A}
cd "${S}"
epatch "${FILESDIR}"/${P}-disable-qa-static.patch
epatch "${FILESDIR}"/${P}-disable-pthread.patch
epatch "${FILESDIR}"/0001-libsandbox-handle-more-at-functions.patch
}


To:
src_unpack() {
unpack ${A}
cd /var/tmp/portage/sys-apps/sandbox-1.6-r2/
tar --lzma -xvf sandbox-1.6.tar.lzma
mv sandbox-1.6/ work/
cd "${S}"
epatch "${FILESDIR}"/${P}-disable-qa-static.patch
epatch "${FILESDIR}"/${P}-disable-pthread.patch
epatch "${FILESDIR}"/0001-libsandbox-handle-more-at-functions.patch
}

Then:
cd /usr/portage/sys-apps/sandbox/; ebuild sandbox-1.6-r2.ebuild manifest

After this edit, sandbox emerged properly, so portage emerged properly too. Everything else worked as expected…

Filed by kargig at 12:13 under Gentoo,Linux
Tags: Gentoo, Linux, lzma, portage, sandbox, upgrade
4 Comments | 9,625 views

Μιας και άρχισα να ετοιμάζομαι για το Fosscomm 2009 πήρα το .kml από το χάρτη (google map) που έχουν φτιάξει τα παιδιά του ΑΤΕΙ Λάρισας και τον μετέτρεψα σε format κατάλληλο για το Destinator μου.

Για όποιον άλλο θέλει να έχει τα σημεία στο Destinator του: Fosscomm 2009 Destinator (.dat) POI

Ελπίζω να μαζέψει αρκετό κόσμο η εκδήλωση 🙂

Υ.Γ. Μην ξεχάσετε να φέρετε εκτυπωμένο το gpg key σας μιας και στα διαλείμματα κάθε μέρας θα γίνει GPG Keysigning Party

Filed by kargig at 23:39 under Greek,Linux
Tags: dat, destinator, fosscomm, fosscomm 2009, google map, gpg, keysigning, keysigning party, kml, larissa, Linux, poi
2 Comments | 10,485 views

During some QoS tests on Linux I needed to measure the traffic of the system in realtime without being able to compile any new software on it. The system had already perl installed so I googled to find a script that could monitor in/out traffic of an interface. The first script I found was this: http://perlmonks.org/?node_id=635792

While it’s actually doing what it says, it only runs just once. I wanted the script to run for a period of time. So I changed it a bit.
Here’s the outcome:
#!/usr/bin/perl
my $dev=$ARGV[0];
sub get_measures {
my $data = `cat /proc/net/dev | grep "$dev" | head -n1`;
$data =~ /$dev\:(\d+)\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+(\d+)\D+/;
my $recv = int($1/1024);
my $sent= int($2/1024);
return ($recv,$sent);
}
my @m1 = get_measures;
while(1) {
sleep 1;
my @m2 = get_measures;
my @rates = ($m2[0] - $m1[0], $m2[1]-$m1[1]);
foreach ('received' , ' transmit') {
printf "$_ rate:%sKB",shift @rates;
}
print "\n";
@m1=@m2;
}

I’ve changed it so that it’s:
a) running continuously until someone presses ctrl+c to stop it,
b) parsing the /proc/net/dev output instead of the ifconfig output. I think this is more efficient/fast than parsing the ifconfig output.

Sample output:

$iftraffic.pl eth0
received rate:1564KB transmit rate:71KB
received rate:1316KB transmit rate:44KB
received rate:1415KB transmit rate:48KB
received rate:1579KB transmit rate:76KB

I am sure that someone with more insight into perl than me can make it even more efficient.

You can also download a version with comments that I made so that one can make the script run for X number of repetitions instead of running until someone stops it.
Download: iftraffic.pl

Filed by kargig at 22:29 under Linux,Networking
Tags: incoming, Linux, monitor, Networking, outgoing, perl, realtime, traffic
4 Comments | 15,615 views

Out of boredom I decided to parse the Linux-Greek-Users (LGU) archives and create some graphs. Then I wrote a few more oneliners to deduct some numbers out of the archives. These numbers may or may not mean anything to someone, it’s entirely up to the reader.. Since the archives contain some amount of spam (not too much though) one must take that into consideration as well while reading the numbers I extracted below…

First thing I did was to download the index file containing the links to the monthly archives since February 1997:
wget http://lists.hellug.gr/pipermail/linux-greek-users/

Then download each month’s archive:
for i in `grep date index.html | cut -d"\"" -f2`; do foo=`echo $i|cut -d"/" -f1`; wget http://lists.hellug.gr/pipermail/linux-greek-users/$i -O $foo-date.html ; done
(more…)

Filed by kargig at 17:00 under Linux
Tags: forum, forum.hellug.gr, HELLUG, LGU, Linux, linux greek users, oneliner, statistics
5 Comments | 183,156 views

I was trying to figure out one 1-liner to delete all empty directories in a tree.
The following should do it’s job:
%find -type d -empty | xargs rm -rvf

BUT! While this works for directories with “regular” filenames, it doesn’t work when there are special characters inside the filename. Consider this for example:

%ls -1
test 1
test2
test _ 3
%find -type d -empty
./test 1
./test2
./test _ 3
%find -type d -empty | xargs rm -rvf
removed directory: `./test2'
%find -type d -empty
./test 1
./test _ 3


Only directory “test2” was deleted. To delete the rest of the directories when they contain “special” characters like whitespace and quotes one needs to modify the command like this:

%find -type d -empty -print0 | xargs -0 rm -rvf
removed directory: `./test 1'
removed directory: `./test _ 3 '

🙂

Filed by kargig at 20:50 under Linux
Tags: delete, directory, Linux, oneliner, xargs
4 Comments | 22,793 views

I’ve just updated by .zshrc so that I can get the exit status of commands on a “right prompt” using zsh’s RPROMPT variable. Exit status appears only if the value is non-zero.

Example usage:

You can find my zshrc and more dot files that I use in my Pages/My dot files

Filed by kargig at 12:32 under Linux,MacOSX
Tags: exit codes, Linux, prompt, zsh
No Comments | 13,270 views

The Task
Last year, me and comzeradd set up a Gentoo server for HELLUG according to our plot to help Gentoo conquer the world. Unfortunately Gentoo is out of HELLUG’s administration policy, all servers must be Debian. We didn’t know that, so after a small flame :), we decided that we should take back the server to somebody’s home and re-install Debian over it, the problem was that the server was located at University of Athens campus which is a bit far from downtown Athens where comzeradd lives. I also live 500km away so we were pretty much stuck. Months passed and nobody actually had enough free time to go to UOA‘s campus and take the server to their house. …In the meantime manji joined us as an extra root for the server.

One Saturday night while chatting at IRC (what else could we be doing on saturday night ??) we had an inspiration, why not install Debian remotely, without taking the server home. Even if everything got eventually borked it couldn’t get any worse than going there, taking the server home and fixing it, just like we would do any way. So we gathered on a new IRC channel with some more friends that are really good with Debian and started the conversion progress.

The Server
The interesting part about the server was that it had 2x250Gb IDE disks. The Gentoo setup had these disks partitioned to 4 software raid devices + swap partitions.
(more…)

Filed by kargig at 20:21 under Gentoo,Linux
Tags: debian, debootstrap, Gentoo, grub, HOWTO, mdadm, no psysical access, raid, raid0, raid1, remote install
11 Comments | 21,047 views

I’ve written a small perl script to parse random entries from the extremely usefull commandlinefu.com website. Quoting from their site:

Command-Line-Fu is the place to record those command-line gems that you return to again and again.

The script code is very “clean”. I can almost say that it’s written in a very python-ish way.
Sample output:%./cfu.pl
CMD: for (( i = 0; i < 100; i++ )); do echo "$i"; done
URL=http://www.commandlinefu.com/commands/view/735/perform-a-c-style-loop-in-bash. Title=Perform a C-style loop in Bash.
Description: Print 0 through 99, each on a separate line.
%./cfu.pl
CMD: rsync -av -e ssh user@host:/path/to/file.txt .
URL=http://www.commandlinefu.com/commands/view/20/synchronise-a-file-from-a-remote-server Title=Synchronise a file from a remote server
Description: You will be prompted for a password unless you have your public keys set-up.

You can get it from here: commandlinefu.com random entry parser perl script

As far as I’ve tested, it works out of the box on default perl installations of Debian, Gentoo and Mac OS X.

Filed by kargig at 01:28 under Gentoo,Internet,Linux,MacOSX
Tags: commandlinefu, debian, Gentoo, MacOSX, oneliner, parse, perl, script
3 Comments | 11,683 views

I am writing this post to provide some statistics on athcool + sata_sil usage. The results are horrible.

Athcool is a small utility, enabling/disabling Powersaving mode for AMD Athlon/Duron processors.
The homepage of the utility has a big fat warning as well:

WARNING: Depending on your motherboard and/or hardware components, enabling powersaving mode may cause:

* noisy or distorted sound playback
* a slowdown in harddisk performance
* system locks or instability

The Gentoo ebuild also has these warnings:

ewarn “WARNING: Depending on your motherboard and/or hardware components,”
ewarn “enabling powersaving mode may cause:”
ewarn ” * noisy or distorted sound playback”
ewarn ” * a slowdown in harddisk performance”
ewarn ” * system locks or unpredictable behavior”
ewarn ” * file system corruption”
ewarn “If you met those problems, you should not use athcool. Please use”
ewarn “athcool AT YOUR OWN RISK!”

Ignoring all these warning I was using athcool for years on my old desktop box filled with 2 IDE disks. Never had any real problem at all, except for a some performance loss. The problem appeared when I first used a sata disk on motherboard’s, Gigabyte GA-7VAXP-A Ulta, sata controller which uses the sata_sil module.
(more…)

Filed by kargig at 10:47 under Gentoo,Linux
Tags: athcool, bug, bug-report, bugzilla, dd, ext3, Gentoo, IDE, Linux, performance, powesaving, sata, sata_sil, vmstat
No Comments | 8,946 views

The Problem
To sum it up, the case is this: many many many web applications were programmed so that they used latin1 collation for their fields inside mysql databases. But most users now use utf8 from within their browsers. What happens is that utf8 characters are getting stored inside latin1 fields, which in return produces chaos! A huge web application that used that kind of madness was WordPress. Luckily (or not) WordPress now uses utf8 everywhere. I’ve known many many many people that got so frustrated when they tried to move from their old WordPress installation to a newer one because all their greek posts couldn’t be exported “easily”, I won’t say “properly” because there are always solutions to problems like this, but all the solutions were not straightforward at all, that they finally dumped the idea of moving the posts and started a new blog.

This is a HUGE problem for many greek (and not only) users and I hope I now have an elegant(?) solution to it.
(more…)

Filed by kargig at 21:14 under Greek,Internet,Linux
Tags: bash, convert, Greek, latin1, mysql, sed, utf8, wordpress
22 Comments | 38,570 views

A couple of days ago I’ve met a guy who has a high traffic blog about tech stuff. The guy was telling me that he has hosting problems and that his blog is getting slower and slower by the day. I’ve offered to help him by providing hosting for him in one of the servers that I administer. After making the transition from his old hosting to my server, which was not an easy thing to do due to latin1 to utf8 conversions that had to be made – it deserves a post of it’s own, I started to notice increased load on my server. Sure his blog had heavy traffic…but could it be that bad ?
(more…)

Filed by kargig at 13:49 under Linux
Tags: caching, db-cache, Linux, mysql, wordpress, wp-cache
10 Comments | 19,592 views